Distributed Archive System, Data Archive Device, and Data Restoring Device with Improved Restoration and Security

1. A distributed archive system for distributing and storing archive target data on n storage devices, where, n is an integer no less than 2, comprising: the n storage devices connected to a communications network; and, a host device communicating with the n storage devices through the communications network, wherein, the host device is configured to: store table data correlating distributing identifiers to storage device groups, where each of the storage device groups includes (n−k+1) storage devices, and k is an integer no more than n; move a pointer over pointer positions along the archive target data in a sequential order, from a leading position of the archive target data toward a trailing position of the archive target data; extract a data fragment from the archive target data at each of the pointer positions, receive a random number generated for the each of the pointer positions to serve as a distributing identifier; look up the table data with the distributing identifier to determine a storage device group corresponding to the distributing identifier; and append the data fragment to a destination file on each of the (n−k+1) storage devices included in the storage device group determined by the distribution identifier for each of the pointer positions.

2. The distributed archive system of claim 1 , wherein, a length of an extracted data fragment is determined independently and randomly for the each of the pointer positions.

3. The distributed archive system of claim 1 , a part or all of the n storage devices are server computers accessible over the communications network.

4. The distributed archive system of claim 1 , wherein dummy data units are added to leading and tailing ends of the archive target data.

5. A distributed archive system for distributing and storing archive target data on n storage devices, where, n is an integer no less than 2, comprising: the n storage devices connected to a communications network; and a host device communicating with the n storage devices through the communications network, wherein, the host device is configured to: store table data correlating distributing identifiers to storage device groups, where each of the storage device groups includes (n−k+1)storage devices, and k is an integer no more than n; prepare n destination files, the n destination files corresponding to the n storage devices respectively; move a pointer over pointer positions along the archive target data in a sequential order, from a leading position of the archive target data toward a trailing position of the archive target data; extract a data fragment from the archive target data at each of the pointer positions, receive a random number generated for the each of the pointer positions to serve as a distributing identifier; look up the table data with the distributing identifier to determine a storage device group corresponding to the distributing identifier; and append the data fragment to the (n−k+1) destination files included in the storage device group determined by the distribution identifier for each of the pointer positions; and send the n destination files to the n storage devices corresponding to the n destination files respectively after a last data fragment is appended to identified (n−k+1) destination files.